{"paper":{"title":"Observation of the Narrow State $X(3872)\\to J/\\psi\\pi^{+}\\pi^{-}$ in $\\bar{p}p$ Collisions at $\\sqrt{s}=1.96 \\TeV$","license":"","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. Anastassov, D. Ambrose, D. Amidei, et al, K. Anikeev, M.G. Albrow, M.H. Ahn, S. Amerio, T. Affolder, T. Akimoto, the CDF II Collaboration: D. Acosta","submitted_at":"2003-12-05T18:16:14Z","abstract_excerpt":"We report the observation of a narrow state decaying into $J/\\psi\\pi^+\\pi^-$ and produced in $220 pb^{-1}$ of $\\bar{p} p $ collisions at $\\sqrt{s}=1.96 TeV$ in the CDF II experiment. We observe $ 730 \\pm 90 $ decays. The mass is measured to be $3871.3 \\pm 0.7 (stat) \\pm 0.4 (syst) MeV/c2$, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"hep-ex/0312021","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/hep-ex/0312021/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}